Aromatic polyester

Abstract

The present invention provides an aromatic polyester which is substantially free from the occurrence of coloration and retains significantly high transparency even after being thermally processed at high temperature and which has high flowability. The aromatic polyester contains a polyhydric phenol residue and a residue of any one of aromatic polycarboxylic acid, halide thereof, and anhydride thereof, and terminals of the aromatic polyester have a structure represented by the formula —C(O)—R. The aromatic polyester has an end-capping rate of 90% or higher and a weight average molecular weight (Mw) ranging from 3,000 to 1,000,000.

1 . An aromatic polyester comprising a polyhydric phenol residue and a residue of any one of aromatic polycarboxylic acid, halide thereof, and anhydride thereof, wherein terminals of the aromatic polyester have a structure represented by Formula (I):
   —C(O)—R  (I)
   
       wherein R represents any one of an aliphatic group, an alicyclic group, a monocyclic aromatic group, a polycyclic aromatic group, a fused aromatic group, a heterocyclic group, and a combination of these groups, at least one hydrogen atom of these groups being optionally substituted with any one of fluorine, chlorine, bromine, iodine, an alkoxyl group, a mercapto group, a sulfenato group, a sulfinato group, a sulfo group, an alkoxycarbonyl group, an acyl group, an alkoxysulfinyl group, an alkylthiocarbonyl group, a thiosulfo group, a cyano group, a thiocyano group, an isocyano group, an isocyanato group, an isothiocyanato group, and a nitro group, the end-capping rate of the polyester is at least 90%, and the aromatic polyester has a weight average molecular weight (Mw) of 3,000 to 1,000,000. 
     
     
         2 . The aromatic polyester according to  claim 1 , wherein the end-capping rate of the polyester is at least 95%. 
     
     
         3 . The aromatic polyester according to  claim 1 , wherein the end-capping rate of the polyester is at least 99%. 
     
     
         4 . The aromatic polyester according to  claim 1 , wherein R in Formula (I) represents any one of a monocyclic aromatic group, a polycyclic aromatic group, a fused aromatic group, and a heterocyclic group, at least one hydrogen atom of these groups being optionally substituted with any one of fluorine, chlorine, bromine, iodine, and an alkoxyl group. 
     
     
         5 . The aromatic polyester according to  claim 1 , wherein R in Formula (I) represents any one of a phenyl group, a naphthyl group, an anthranyl group, and a phenanthryl group, at least one hydrogen atom of these groups being optionally substituted with any one of fluorine, chlorine, and a methoxyl group. 
     
     
         6 . The aromatic polyester according to  claim 1 , wherein R in Formula (I) represents any one of a phenyl group and a naphthyl group. 
     
     
         7 . The aromatic polyester according to  claim 1 , wherein R in Formula (I) represents a phenyl group. 
     
     
         8 . The aromatic polyester according to  claim 1 , wherein the polyester has a weight average molecular weight (Mw) of 20,000 to 100,000. 
     
     
         9 . The aromatic polyester according to  claim 1 , wherein the polyester has a weight average molecular weight (Mw) of 25,000 to 80,000. 
     
     
         10 . The aromatic polyester according to  claim 1 , wherein the polyester has a weight average molecular weight (Mw) of 25,000 to 60,000. 
     
     
         11 . The aromatic polyester according to  claim 1 , wherein a melt flow rate (MFR, unit: g/10 min, and measurement conditions: 320° C. and a load of 10.0 kg) is at least 15.0. 
     
     
         12 . The aromatic polyester according to  claim 1 , wherein a melt flow rate (MFR, unit: g/10 min, and measurement conditions: 320° C. and a load of 10.0 kg) is at least 50.0. 
     
     
         13 . The aromatic polyester according to  claim 1 , wherein the polyhydric phenol is bisphenol A, and any one of the aromatic polycarboxylic acid, halide thereof, and anhydride thereof is terephthaloyl dichloride and/or isophthaloyl dichloride. 
     
     
         14 . The aromatic polyester according to  claim 1 , the aromatic polyester is used for optical applications. 
     
     
         15 . A method of preparing an aromatic polyester by a reaction of polyhydric phenol with any one of aromatic polycarboxylic acid, halide thereof, and anhydride thereof, the method comprising the steps of:
 (i) adding a compound represented by Formula (II):
   X—C(O)—R  (II)
 
   
       wherein, X represents any one of chlorine, bromine, and iodine, and R represents any one of an aliphatic group, an alicyclic group, a monocyclic aromatic group, a polycyclic aromatic group, a fused aromatic group, a heterocyclic group, and a combination of these groups, at least one hydrogen atom of these groups being optionally substituted with any one of fluorine, chlorine, bromine, iodine, an alkoxyl group, a mercapto group, a sulfenato group, a sulfinato group, a sulfo group, an alkoxycarbonyl group, an acyl group, an alkoxysulfinyl group, an alkylthiocarbonyl group, a thiosulfo group, a cyano group, a thiocyano group, an isocyano group, an isocyanato group, an isothiocyanato group, and a nitro group, 
       in an amount of 0 to 40 mol % relative to the total fed amount of any one of the aromatic polycarboxylic acid, halide thereof, and anhydride thereof to promote a reaction, and
 (ii) adding the compound represented by Formula (II) in an amount of 3 to 80 mol % relative to the total fed amount of any one of the aromatic polycarboxylic acid, halide thereof, and anhydride thereof in step (i) to further promote the reaction of the resultant aromatic polyester. 
 
     
     
         16 . The method of preparing an aromatic polyester according to  claim 15 , wherein the compound represented by Formula (II) is added in an amount of higher than 0 mol % and up to 40 mol % in step (i). 
     
     
         17 . The method of preparing an aromatic polyester according to  claim 15 , wherein R in Formula (II) represents any one of a monocyclic aromatic group, a polycyclic aromatic group, a fused aromatic group, and a heterocyclic group, at least one hydrogen atom of these groups being optionally substituted with any one of fluorine, chlorine, bromine, iodine, and an alkoxyl group. 
     
     
         18 . The method of preparing an aromatic polyester according to  claim 15 , wherein R in Formula (II) represents any one of a phenyl group, a naphthyl group, an anthranyl group, and a phenanthryl group, at least one hydrogen atom of these groups being optionally substituted with any one of fluorine, chlorine, and a methoxyl group. 
     
     
         19 . The method of preparing an aromatic polyester according to  claim 15 , wherein R in Formula (II) represents a phenyl group. 
     
     
         20 . The method of preparing an aromatic polyester according to  claim 15 , further comprising step (iii) of purifying a solution produced through the reaction in step (i), step (iii) being performed between steps (i) and (ii). 
     
     
         21 . The method of preparing an aromatic polyester according to  claim 15 , wherein the polyhydric phenol is bisphenol A, and any one of the aromatic polycarboxylic acid, the halide thereof, and anhydride thereof is terephthaloyl dichloride and/or isophthaloyl dichloride.